[Chaos-l] lunar filter

[Robert Nielsen]

Michael,

First of all, definitely get some sort of filter ... the moon is so 
bright I see dark spots for minutes after viewing it sometimes (like at 
Morehead observing sessions).

And if you can afford it, I'd go with John's suggestion - the variable 
polarizing filter.  The reasoning (and likely the reason why there is a 
13% and a 25% non-variable filter) is because the brightness of the moon 
varies greatly ... from when it is full (and I can project an image onto 
my palm six inches from the eyepiece) to when it is a quarter or less.  
With the variable version, you can set the brightness as you like.

Robert  (who is moving to a 2" filter this Christmas ... if Santa thinks 
I've been a good boy)

Michael Hrivnak wrote:
> I would like to get a lunar filter for use with my 8" dob.  Should I get one 
> that passes 13% of light, 25%, or one of these variable ones that are 
> adjustable between about 1-40%?  Or maybe I should get the 13 and 25?
>
> I'm would appreciate any insight on how the adjustable ones work.
>
> Thanks,
> Michael
>   
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